A standardized bus, such as a bus compliant to USB (Universal Serial Bus) specification developed by USB IF (USB Implementers Forum), is useful for interconnecting two electronic apparatuses, e.g., a host and a device. Via the bus, the device can cooperate with the host to expand functionalities of the host. Please refer to FIG. 1 illustrating two electronic apparatuses 10a and 10b respectively as a host and a device connected by a bus 11 which is compliant to a bus specification, e.g., the USB specification. The bus 11 mechanically connects via two mated physical connectors 11a and 11b respectively disposed on the electronic apparatuses 10a and 10b, and allows signaling (transmitting and/or receiving) between the electronic apparatuses 10a and 10b at standard speed(s) compliant to the bus specification.
For example, the apparatus 10a may be a desktop computer, a notebook computer, a tablet computer, a set-top box, a media player, a game console, etc., while the apparatus 10b may be a wireless (e.g., Wi-Fi or Bluetooth) adapter or dongle which establishes wireless connection enabling the apparatus 10a to transmit and/or receive signals to and/or from a wireless network (not shown) or a wireless accessory (e.g., keyboard, mouse, earphone, headset or glasses for experiencing virtual or augmented reality, not shown).
Modern bus specification tends to aggressively raise its standard speed to meet demands of high-rate data interchange. For example, besides a standard speed of 480 Mbps (megabits per second) named as HighSpeed, the USB 3.0 specification introduces another standard speed of 5 Gbps (gigabits per second) named as SuperSpeed. However, bus signaling at such standard speed seriously interferes and degrades wireless connection. A USB-compliant bus signaling at SuperSpeed of 5 Gbps may form a power spectrum density as modeled in FIG. 2, which leaks considerable power at frequency of wireless connection, e.g., 2.4 GHz. The power leakage at 2.4 GHz then causes undesired interference to wireless connection. For example, if the wireless connection is for wireless networking (e.g., Wi-Fi networking), desired signals of the wireless networking will be de-sensed by the undesired interference and therefore suffers from low signal-to-noise ratio and high bit error rate; if the wireless connection is for wireless accessory like a mouse, mouse pointer or cursor at the host may even fail to respond movement of mouse.